This collection of earthquake data displays large magnitude (6.5 and above) earthquakes dating back to 1900. Each earthquake is represented by a colored circle located at the approximate location of the epicenter. The color of the circle represents the number of fatalities and the size of the circle represents the the magnitude of the earthquake. In addition, the depth of the earthquake is represented by the height of the circle above the earth. In other words, the deeper the earthquake, the higher the circle is above the ground.
The information balloons also contain detailed information about the earthquake and links to webpages with more information. You can also filter the data by different magnitude ranges and use the time slider feature of Google Earth to view the data over time.
Note, when the file first loads you will need to expand the time slider to see some data.